Machines for packaging articles such as beverage cans and bottles into sleeve-type carriers or cartons are capable of moving carton sleeves in a downstream direction while at the same time inserting the articles through open ends of the sleeves, after which the end flaps of the carton are folded over to form the end panels. The articles are moved into the machine area by an infeed conveyor and are typically moved to the loading area by conveying means, such as a flight bar or a conveyor, after which they are guided into the sleeves by guide rails. While effective in introducing articles into a sleeve, this method is at times susceptible to jamming and does not normally have the capability of inserting the articles as swiftly as desired into the sleeve.
Another method of introducing articles into a carton makes use of a pusher plate assembly, in which a series of plates are moved at an angle toward the loading station at a speed whereby the downstream component of movement of the plates is the same as the speed at which the carton sleeve and the articles are moving. The component of movement of the plates which is at right angles to the downstream direction causes the plates to push the articles at the loading station into an adjacent carton sleeve. While this loading action enables articles to be more positively pushed into a carton, the mechanism for accomplishing it tends to create other problems. For example, in one design the path of movement of the pusher plates is controlled by cams, resulting in the mechanism being quite large and labor intensive to maintain. In another design the pusher plates are connected to an endless chain and tend to move out of parallel when making the turns between the upstream and downstream runs. This is not a desirable condition since the less smooth the movement of the plates and chain, the more stresses are introduced into the mechanism.
It would be very desirable to be able to positively push articles to be packaged into a carton sleeve without encountering the problems noted above.